[119/119] isdn: hfc_usb: Fix read buffer overflow

Greg KH
2009-12-07T00:15:33Z

[-- Attachment #1: isdn-hfc_usb-fix-read-buffer-overflow.patch --]
[-- Type: text/plain, Size: 1039 bytes --]

2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
From: Roel Kluin <roel.kluin@gmail.com>

commit 286e633ef0ff5bb63c07b4516665da8004966fec upstream.

Check whether index is within bounds before testing the element.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/isdn/hisax/hfc_usb.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/isdn/hisax/hfc_usb.c
+++ b/drivers/isdn/hisax/hfc_usb.c
@@ -817,8 +817,8 @@ collect_rx_frame(usb_fifo * fifo, __u8 *
}
/* we have a complete hdlc packet */
if (finish) {
- if ((!fifo->skbuff->data[fifo->skbuff->len - 1])
- && (fifo->skbuff->len > 3)) {
+ if (fifo->skbuff->len > 3 &&
+ !fifo->skbuff->data[fifo->skbuff->len - 1]) {

if (fifon == HFCUSB_D_RX) {
DBG(HFCUSB_DBG_DCHANNEL,